Spark plug



Nov. 14, 1961 w. D. HE'NsLEY SPARK PLUG vFiled oct. 12, 1959 lasINVENTOA a@ WIL.IAM D HENSLEYI 1e/vir ette ' This invention relates tointernal combustion engines and, more particularly, to -a spark plugtherefor.

Ordinarily, water and dirt accumulating upon the top of spark plugsadjacent to the motor block is responsible for causing malfunctioning ofthe spark plug, inefficient engine penformance, and the like. It istherefore 4an object of the present invention to provide a spark plugfor internal combustion engines which has a self contained protectiveshield for preventing the accumulation of such foreign matter upon thespark plug, so as to substantially increase the operating etliciencythereof.

Another object of the present invention is to provide a spark plug forinternal combustion engines of the type described having an electrode ofunique design which will effectively increase the performance of theengine and assure a proper combustion of the fuel.

Still another object of the present invention is to provide a spark plugfor internal combustion engines of maximum performance efficiency, whichcan be manufactured in larve quantities at a relatively low cost.

All of the foregoing and still further objects and advantages of thisinvention will become apparent from a study of the followingspecification, taken in connection with the accompanying drawing,wherein:

FIGURE 1 is a perspective view of a spark plug made in accordance withthe present invention;

FIGURE 2 is a longitudinal cross sectional view of the spark plug shownin FIGURE 1 in actual use;

iFIGURE 3 is a bottom plan view of the spark plug shown in FIGURE 2;

FIGURE 4 is a top plan view of the spark plug shown in FIGURE 2;

lFIGURE 5 is a transverse cross sectional view taken along line 5 5 ofFIGURE 2;

FIGURE 6 is an enl-arged perspective view of a slightly modiiied form ofelectrode forming a part yof the present invention;

FIGURE 7 is a view similar to FIGURE 6, showing a still .furthermodilied form of construction; and

FIGURE 8 is a view similar to FIGURE 6, showing still another form ofthe present invention.

Referring now to the drawing, and more particularly to FIGURES 1 to 5thereof, a spark plug 10 made in accordance with the present inventionis shown to include an electrically conductive main body portion 12having an externally threaded stem 114- yfor threaded engagement withinthe provided opening of an engine block :15. The main body portion 12also includes a hexagonal section 16 for effecting the installation andremoval of the spark plugs with respect to the engine block 15.

The interior of the main body member 12 is substantially iilled with adielectric material 18, such as porcelain, which serves as a shield orinsulator for a conducting rod 24 extending th-roughout the entirelength of the spark plug. A terminal 26 is secured to one end of the rod24 for connection to a source of electrical energy used for thecombustion engine. The opposite end of the rod 24 includes an electrode30 of generally circular con- 3,009,075 Fatented Nov. 14, 1961figuration having a plurality of reentrant indents 32 which distributethe spark evenly adjacent to the engine block 15.

A canopy, in the form of a skirt 20, also of dielectric material,overlies the main body member 12, is integral with the material 18 andinsulator 22 and protects the top of the main body member 12 from thedeposit of moisture, water, oil, and other foreign matter. All of theupwardly facing surfaces of the spark plug are curved or s-lopedsufficiently to prevent the formation of puddles, and depressed areas,which would retain `such foreign matter and interfere with the properoperation of the engine. Since the electrode 30 extends into the engineblock 15 in substantially spaced relationship with the innermostextremity of the main body member stern 14, there is little interferencewith the proper formation of a spark between the adjacent parts.

In FIGURE 6 of the drawing, a slightly modified form of electrode 34 isshown wherein the circular disc 36 thereof is imperforate and of smoothsided configuration, which construction may be preferable in certaintypes of engines. In FIGURE 7 of the drawing, an electrode 38 is shownto include a plurality of radially outwardly extending arms 40,circumferentially equally spaced apart to properly distribute the sparkin all directions.

In FIGURE 8 of the drawing, still another form of electrode 42 is shownto include a hook-shaped terminal portion 44 which will more effectivelydirect the spark toward the engine block, for certain types of engineperfoi-mance.

It will now be recognized that a spark plug has been provided which isextremely effective for all types of internal combustion engines, whichhas self contained means for preventing the deposit of foreign matter,and which will provide maximum engine performance.

While this invention has been described with particular reference -tothe construction shown in the drawing, it is to be understood that suchis not to be construed as imparting limitations upon the invention,which is best defined by the claim appended hereto.

Having thus described my invention, I claim as new and desire to secureby Letters Patent:

A spark plug comprising, in combination, a conductive main body portion,a conductor extending longitudinally through said main body portion, aninsulator, said insulator insulating said conductor from said main bodyportion and having a dielectric shield, a terminal connected to oneouter end of said conductor, an electrode carried by the opposite end ofsaid conductor, a canopy integral with said shield overlying said mainbody portion, said canopy comprising a skirt integral with said shieldand spaced above and ared outwardly with respect to said main bodyportion.

References Cited in the lile of this patent UNlTED STATES PATENTS1,122,297 Muldoon Dec. 29, 1914 1,215,430 Thordarson Feb. 13, 19171,312,850 Johnson Aug. l2, 1919 1,358,292 Collins Nov. 9, 1920 1,371,488Jacobson Mar. 15, 1921 1,388,343 Hull Aug. 23, 1921 1,498,984 Tra-mpcJune 24, 1924 1,794,673 Creager Mar. 3, 1931 2,269,076 Boll Jan. 6, 1942

